The document discusses cell theory and evidence that supports it. It states that all living things are made of cells, cells come from other cells, tissues are made of individual cells, and organelles cannot live independently of cells. It provides examples of unicellular organisms carrying out life functions through metabolism, response, homeostasis, growth, reproduction, and nutrition. It also discusses exceptions like muscle cells and the debates around viruses.

1. Topic 2 Cells

10. Amoeba on the move!

11. Diatoms

12. Multicellular cells show emergent properties Emergent properties are ones that come about when individual parts of a system interact with each other. On their own, the individual parts cannot do what they can do together. The whole is greater than the sum of its parts. A cell can do much more than the individual parts or organelles can do. A protein can do more than the amino acids that its made up of.

13. Think of these 3 parts: 1. A small metal cup 2. A glass bowl 3. A piece of tugnsten wire Individually they have no function, but when they are together:

16. Conclusion Large organisms, the rate of exchange of substances with their surroundings occurs more slowly Cell radius (r) 0.25 units 0.5 units 1.25 units Surface area 0.79 units 3.14 units 7.07 units Volume 0.06 units 0.52 units 1.77 units SA: Volume 13.17:1 6.04:1 3.99:1

18. Comparisons of microscopes: Light microscope is more limited by its resolving power but allows observation of living organisms, movement and processes Transmission electron microscope is used to study the internal structure of the cell Scanning electron microscope is used to study the surface of a sample

20. Units of size

30. Embryonic stem cells/adult stem cells

34. Two kinds of cells: prokaryotic and eukaryotic Prokaryotic Small- 1 micron Lack nucleus and intermembranous systems Have cell wall DNA: one main circular chromosome and additional DNA in plasmid

35. Two kinds of cells: prokaryotic and eukaryotic Prokaryotic Eukaryotic Small- 1 micron Larger-10-100 microns Lack nucleus and intermembranous systems Organelles bound by membranes Have cell wall May have cell wall DNA: one main circular chromosome and additional DNA in plasmid DNA: in the nucleus, double stranded, no plasmid

37. Generalized prokaryotic cell

39. Prokaryotic cells divide by binary fission

40. EUKARYOTIC CELLS

42. NUCLEUS

44. RIBOSOMES

46. ENDOMEMBRANE SYSTEM Endoplasmic reticulum

49. Golgi Apparatus

51. Lysosome